Final answer:
The statement that surface barriers provide innate immunity against pathogens is true. They include the skin and mucous membranes, which offer physical and sometimes chemical defenses against pathogens, standing as the body's first line of defense.
Step-by-step explanation:
Surface barriers, such as the cutaneous (skin) and mucous membranes, indeed provide innate immunity against pathogens. This statement is A. True. These barriers work as the body's first line of defense, preventing pathogens from entering the body and establishing an infection. The skin provides several layers of protection, including a layer of dead, keratinized epithelial cells that are not conducive to bacterial growth and are regularly shed, removing microbes. The mucous membranes produce sticky mucus that traps pathogens, and areas like the upper respiratory tract have cilia that move trapped pathogens up to the mouth to be expelled.
In addition to physical protection, these surfaces can have chemical properties that fight off pathogens, such as lowering pH, secretion of toxic lipids, and physically flushing away microbes through sweat and other secretions. When these barriers are breached due to abrasions or punctures or when pathogens collect in large numbers, the innate immune response includes inflammation and the activity of specialized cells and proteins to fight off the invaders.